Device for actuating and controlling electric motors.



PATENTED MAY 19, 1903.

0. c. BRITSGH. DEVICE FOR AGTUATING AND CONTROLLING ELECTRIC MOTORS.

4 SHEETS-SHEET 1.

APPLIOAT-IONIILED NOV. 28, 1902.

H0 MODEL.

1 PATBNIED'MAY 19,1903.

. I 0. c. BRITS'GH. "DEVICE FOR AGTUATINGAND CONTROLLING ELEGTBIGMOTORS'.

.APPLIOATIOR'I'ILED NOV- 28, 1902.

4 "sums-anam- .2.

no IODEL:

n4: NORRIS PEYERS co. PNDTO L|YNO., WASHINGTON, u. c.

my. 728,537. PATENT-ED Mn 19, 1903.

0. c. :BRIITYSGIH, I v DEVICE FORAGTUATING AND CONTROLLING ELEGTRIG MOTORS. .vurmonlon Hummov. 28, 1902. I0 uonnL. 4 sums-auxin a.

UNITED STATES Patented May 19, 1903.

PATENT! OFFICE.

OTTO C. BRITSOH, OF'MASPETH, NEW YORK, AS S IGNOR lO DAVID \VALD,

OF NEW YORK, N. Y.

DEVICE FOR ACTUATING AND CONTROLL'ING ELECTRIC MOTORS.

SPECIFICATION forming part of LettersPatent No. 728,537, dated May'19, 1903.

Application filed November 28. 1902. Serial Nol 132,986. (No model.) i

To all whom. it may concern:

Be it known that I, OTTO, O. BRITSCH, a citizen of the United States, residing at Maspeth, in the county of Kings and State of New York, have invented an Improvement in Devices for Actu'ating and'Controlling Electric Motors, of which the following is a specification.

My invention relates to an electric device mechanically actuated for starting, stopping,

and controlling the speed of electric motors,

of the electric circuit aseries'of resistances are brought in which reduce thelpowerof the electric current supplied to the motorterminals, so that the motor starts at a minimum speed only. This speed inayafterwardbe progressively increased by a step-by-step cutting out of the resistances and consequent increase of the power of the electric current until all the resistances are cut out and the motor is running at full speed by the full strength of the current. This condition maintains so long as the foot-powerapplied by the operator to the treadle is constant and holds under tension a spring structure of sufficient strength to effect the return movement; but as soon as the foot-power is released this spring structure comes into play to apply a brake to stop the motor and to simultaneously break the electric-circuit through the electrical device. I

In the drawings, Figure l is a diagrammatic View representing a motor, detached parts of the'device of my invention, and resistances in series. Fig. 2 is a front elevation of the .major part of a complete strucmm. Fig. 3 is a side elevation of the same. Fig. 4 is a plan with the motor-base and cover of the frame and underlying parts removed for clearness. Fig. 5 is a vertical cross-section at 50 m of Fig. 4. Fig; 6 is an end elevation of the ribbed huh and a section of its shaft and insulating-sleeve, and Fig. 7 is an elevation of the cam on the end of said shaft in two of its positions with part of the lever operating the same.

The motor device or structure a may be of any desired or welt-known character, the

same forming no partot' my present inven-' tion. This motor structure is shown as havinga shaft Z, a pulley Z for aband extending therefrom to the sewing-machine or other;

mechanism to be driven, and a brake-wheel Z? In the diagrammatic view, Fig. 1, the mofor structure a, is illustrated as of conventional form. In this figure, b b, c c 0 0 0 and d cl are circuit-selectors in the form of spring-blades. ff are line-wires connected, respectively, to the circuit-selectors b and d, the Wirefextending to the circuit-selector b and the wire f from thecircuit-selector d. 'e isacontact-cylinder having a longtapering rib. e','a'n'd e isa ribbed hub on the same A shaft, the radius of which parts is appreci- 4 ably greater than that of the major portion ofthe cylinder. g g are wires for the electric current from the motor. 1, 2, 3, 4, 5, and 6 are wires from the circuit-selectors to the resistances 7, 8, 9, 10, and ll', which are shown in this diagrammatic viewas in groups. The wire g from the motor connect's to thef through I) e b, the wire I through the series I of resistances 7, 8, 9, l0, and 11 by the wire 9 to the motor, through the motor and by the Wire g to the circuit-selector d, the ribbed hub 6 the circuit-selector d, and away. by

the wire f, in this manner starting the m0-= tor at a minimum speed only, all of the resistances being in evidence to reduce the speed and retard the current. If this contact-cylinder 6, with its rib e and ribbed hub e is turned a slightly greater distance, then the tapering rib e is brought into contact both mechanically and electrically with the circuit-selector c, or progressively with 0', c c and 0 the circuit-selectors b b and d 61' remaining constant in electrical contact with the ribbed portion of said contact-cylinder and hub. W'hen the circuit-selector c is brought into contact with the rib e, the electric current taking the shortest route passes from the wire fthrough the circuit-selector b to the circuit-selector c, by the wire 2 through the resistances 8, l), 10, and 11, and by the wire g to the motor. When contact is made between the rib e and the circuitselector 0, the resistances 7 and 8 are cut out, and so when the circuit-selector c is brought into contact progressively with the rib c the resistances 7, 8, and 9 are cut out. When the circuit-selector 0 comes in contact in the progressive movement with the rib e, the resistances '7, S, 9, and 10 are cut out, and, finally, when the circuit-selector c is in the progressive movement brought in contact with the rib c all of the resistances are cutout and the current flows from the wire fthrough the circuit-selector b, the rib e of the contact-cylinder,by the circuit-selectorc, wire 6, wire 9 to the motor, through the motor by g to the circuit-selector d,by the ribbed hub e to the circuit-cylinder d, and away by the wire f. \Vith this progressive movement and the cutting out of the several resistances the power of the current is gradually increased and the speed of the motor progressively increased thereby until, finally, when allof the resistances are cut out, the current is flowing at its full power and the motor running at its full speed. Reverse movement imparted to the contact-cylinder 6, its rib c, and the ribbed hub e gradually throws in these resistances into the circuit to assist in slowing down the motor, and the circuitis broken the moment the juxtaposed edges of the tapering rib e and the ribbed hub 6 come away from the circuit-selectors I) b and cl d to completely shut off the current.

The structure in which the operations hereinbefore described are electrically and mechanically performed comprise the following: A plate-base 0 is secured to the base ofthe motor structure in any desired manner, and this base is provided with an integral post 0, abracket 0 and a cylinder 0' at the end of the bracket, there being a rising portion of said bracket formed therewith and with said cylinder, and which part serves as a point of attachment for parts hereinafter described. The frame it, of L shape, is provided with a bracket h and a clamping-screw 12 through the end of the bracket, by which said frame is removably secured to the top ofa bench or table. (Shown in Fig. 3 by dotted lines.) This frame it is provided with a cover '21, having ribs 16 and lugs 17, and at one end said cover is provided with a lug through which passes the adjusting-screw ct. This screw passes into a portion of the base 0 and is adapted in its rotation to draw said base along upon the cover it, the ribs 16 thereof forming guideways for the plate 0, so as to adjust the position thereof with reference to the brake device hereinafter described and the band extending to the machine being driven. Aplate 18 fits within the lugs 17 and is held to the base 0 by a bolt 19, said plate and bolt moving with the base 0, the plate being beneath the edges of the lugs 17, said plate and lugs serving to firmly hold down the base 0 and the motor structure a to the cover 07,, which cover in turn is secured to the frame it, preferably by corner-screws passingdown through apertures in said cover into perforations in the corners of said frame. (Shown in Fig. 4:.) Slabs of rigid insulating material t and 7c are within the frame It, the slab 7r occupying a horizontal position in the upper portion of said frame and the slab 7L occupying a vertical position in the forward part of said frame and secured thereto by the screws t. Metal plates 13, occupying a vertical position, come directly behind the circuit-selectors l) b, c c c 0 c and d (1, and screws 14 pass through the circuit-selectors and through said metal plates into the slab i, so as to hold said parts in position, and I may, as shown in Figs. 2 and 5, hold said circuit-selectors and metal plates together by rivets. I also employ screws 15, agreeing in number with the circuit-selectors and plates 13 and which pass through the upper portions of said metal plates 13 into the slab tand serve the twofold purpose of securing said plates to said slabs and holding the ends of the wires f, 1, 2, 3, 4:, 5, 6, g, and j'" in position to said metal plates 13, the said wires by preference being located at the back of the'slabiland having their ends passing through apertures in the slab to mechanical and electrical contact with the screws 15. Fastening devices, not necessarily the screws 1e and 15, are to be employed. A band m, preferably of spring metal, extends over the brake-wheel l At one end of this band there is an adjustable yoke device m, connecting with the post 0 of the base 0, and the other end of this band is connected to a stem m which passes down through the cylinder 0 there being a head at the upper end of said stem for the connection thereto of the band 'm, and nuts at the lower end of said stem, with a helical spring m within the cylinder 0 between the nuts on the lower end and the head of the cylinder through which the stem m passes, the tendency of said spring being to draw the band m against the surface of the brake-wheel Z with sufficient force and consequent friction to arrest the movement of the motor structure. A lever 7', pivoted at 20 to the upright portion of the bracket 0 is at one end forked to straddle the stem 1% and at the other end provided with an aperture receiving the hooked end of a link22. A bell-crank levers is pivoted at 21 to the side of the frame 71. One arm of this lever is provided, adjacent to its pivot, with an aperture for the other end of the link 22 and at its free end with an aperture for the rod 15. The other arm of the bellorank lever is provided with a jaw s. The contacting cylinder e, hereinbefore described, is mounted between the sides of the frame It in the lower front portion, the shaft 24 thereof passing through the sides of the frame, and on one end of this shaft I provide a cam 11.. (Shown especially in Figs. 3 and 7.) Between the shaft 24 and the contact-cylinder e and ribbed hub c and between the sides of the frame it is placed an insulating-sleeve 25, which prevents the electric current passing between the said contact-cylinder and ribbed hub or from either of said parts to the shaft 24 or therefrom to other parts of the mechanism. There is a'stop 26 on the side of the frame h adjacent to the cam u, a spring 27' connected to the lower part of the frame h and projecting'slightly beyond the end adjacent to said cam u and coming in the path of said cam, and there is astop 28 also upon the side of the frame 71. for limiting the upward movement of the bell-crank lever 8. Figs. 2 and 3 represent the normal position of rest of said parts, in which the spring m draws upon the band an to produce a frictional hold on the brake-wheel 1 said stop 28 holding the lever a" from being drawnin contact with the upper end of the cylinder 0 and in this position the cam u, as shown, agrees with the position of the contact-cylindere and ribbed hub e in Fig. 5, where the same is not as yet'in mechanical or electrical contact with any of the circuit-selectors, said cam being held in a position of rest against the stop 26. The operator may now press upon the treadle and pull upon the rod t.

This movement swings the bell-crank lever s and by the link 22 swings the lever r on its pivot, strains the helical spring m and releases the tension upon the band m, so that the motor is free to start. Simultaneously with this movement the jaw s of the bellcrank lever swings the cam u in proportion to the extent of movement of said parts, the first portion of the movement bringing the contact-cylinder e and the ribbed hub e into engagement with the circuit-selectors b b and d d and thereafter progressively with the circuit-selectors c, 0, c 0 or 0 so as to apply a minimum current to the motor or progressively by cutting out the resistances an increased strength of current up to a maxi mum, where the motor develops its full speed and power. Fig. 7-shows the cam ttand the jaw s of the bell-crank lever in the opposite position to that shown in Fig. 3 and in the positionof extreme movement of the contact-cylinder e and ribbed hub e at which all of the resistances have been cut out and the full strength of the current is flowing from the wire'f through the. circuit-selector b, the rib e of the cylinder, circuit-selector 0 the wire. 6, wire g, the motor, the wire g, the circuit-,

' and by the wire f The dotted position, Fig.

'7, shows the return movement substantially at the line of electrical separation of the ribs of the cylinder e and hub e from the circuitselector's. The spring 23 is of sufiicient strength to turn the cam uand shaft 24, with the parts connected therewith, from the fullline position, Fig. 7, to the dotted-line position, Fig. 7, where the other end of the cam is arrested momentarily by the spring 27. When this movement is arrested, the spring 23 is put under tension and moved until the same strikes one side of the jaw s, at which no further yielding is possible. The jaw then with force and a quick movement,which the spring 23 accelerates, returns the cam u from the dotted-line position, Fig. 7, to the.

full-line position, Fig. 3, thusinstantly breaking the electrical circuit between the contact cylinder and hub and the various circuit-selectors, thus rendering any arcing impossible.

From the foregoing description it will be apparent that this structure is moved in one 0 direction positively by the power applied by the foot of the operator to a treadle and the rod tand that the return movement is efiected automatically and substantially instantaneously by the expansive action of the helical 9 5 spring m which at the same timeapplies the band mto the brake-wheel Z to arrest the motor and break the electric circuit through the machine.

In the diagrammatic view, Fig. 1, and as I00 hereinbefore described, 7, 8, 9, 10, and 11 represent the resistances in groups, the same being shown by zigzag lines. In the structure described I prefer that these resistances shall bein the form of helices 29, of wire, with in superposed series, one series of which, according to Fig. 4, are parallel to each other no and parallel to the sides of the frame h, and the other series of which are parallel to each other and at an angle to the parts of the frame, and these series are preferably separated by layers 31 of insulating material, r15

such as sheets of asbestos.

I claim asmy invention v 1. The combination with an electric motor, of devices normally applying tension to brake the same, means operated by foot-power to release said devices, devices actuated simultaneously by said means for completing an electric circuit through the motor and for progressively increasing the current therein, and means for momentarily'retarding the return movement of the latter devices and insuring a quick motion at the end of said movement for breaking the electric circuit so as to prevent'the possibility of arcing.

2. The combination with an electric motor, of a series of resistances in groups, aseries of aline'd circuit 7 selectors in three predetermined. groups, line-wires connected to the first and extending from the.,1ast.o said (til Y &

cuit-selectors, circuit-Wires connecting the respective groups of resistances and the motor with the remaining and intermediate circult-selectors, a rotary device and a ribbed hub upon and insulated from acommon shaft, means for progressively rotating said shaft and the devices carried thereby to bring the same into contact with the circuit-selectors in a predetermined and progressive manner, substantially as and for the purposes set forth.

3. The combination with an electric motor, of a series of resistances in groups, a series of alined circuit selectors in three predetermined groups, line-wires connected to the first and extending from the last of said circuit-selectors, circuit-wires connecting the respective groups of resistances and the motor with the remaining and intermediate circuit-selectors, a rotary device in the form of a ribbed cylinder, and a ribbed hub upon and insulated from a common shaft, means for progressively rotating said shaft and the devices carried thereby to bring the same into contact with the first and last group of circuit-selectors and progressively with the circuit-selectors of the intermediate group, sub stantially as and for the purposes set forth.

4. In a device for actuating and controlling electric motors, the combination with a motor and a series of resistances in predetermined groups, of a series of three groups of circuitselectors, twoin the first and last groups and two or more in the intermediate group, a shaft, an insulating-sleeve around the same, a cylinder having a long tapering rib and a ribbed hub mounted upon the insulated sleeve of said shaft at a predetermined distance apart, and means forimpartinga partial rotation to said shaft and the parts connected therewith in opposite directions to make contact simultaneously with the. circuit-selectors of the first and third groups and progressively with.

the circuit selectors of the intermediate group, substantially as set forth.

5. In a device for actuating and controlling electric motors, the combination with a base supporting the motor and a post and cylinder carried thereby and a brake-wheel upon the shaft of the motor, of a band extending over said brake-wheel, an adjustable yoke device at one end of the band connected to said post, a stem connected to the other end of the band and passing through the head of said cylinder, a helical spring within the cylinder around said stem and between the head of the cylinder and nuts upon the end of the stem normally exerting a pressure-applying tension to the band upon the brake-wheel, and devices actuated by foot-power for applying tension to said spring to release the band upon the brake-wheel, and for simultaneously establishing an electric circuit to the motor.

6. In a device for actuating and controlling electric motors, the combination with a base supporting the motor and a post and cylinder carried thereby and a brake-wheel upon the shaft of the motor, of a band extending over said brake-wheel, an adjustable yoke device at one end of the band connected to said post, a stem connected to the other end of the'band and passing through the head of said cylinder, a helical spring within the cylinder around said stem and between the head of the cylinder, and nuts upon the end of the stem normally exerting a pressure-applying tension to the band upon the brake-wheel, a pivoted lever having a forked end straddling said stem, a bell-crank lever, a link connecting one arm of the bell-crank lever with the other end of said pivoted lever, a rod from the said arm of the bell-crank lever to a footoperated device, a cam at one end engaged by the other arm of said bell-crank lever and to which a forward and backward swinging movement is imparted by said lever, and a device upon the shaft of said cam, and electrical devices engaged thereby for making and breaking the electric current to said motor simultaneously with the movement of said cam and bell-crank lever, substantially as set forth.

7. In a device for actuating and controlling electric motors, the combination with predetermined groups of circuit-selectors,of a shaft, a cam on one end of said shaft, a stop for limiting the cam in its opposite positions, an insulating-sleeve upon said shaft, a ribbed cylinder and ribbed hub spaced apart upon the insulating-sleeve of said shaft and coming beneath the free ends of the said groups of circuit-selectors, devices operated by footpower for moving said cam in one direction gradually through its entire movement and for moving said cam in the opposite direction with a partial yielding movement, and a spring-stop for momentarily arresting the return movement of the cam so as to effect the sudden and complete break of the electric circuit.

8. In a device for actuating and controlling electric motors, the combination with predetermined groups of circuit selectors, of a shaft, a cam on one end of said shaft, a stop for limiting the cam in its opposite positions, an insulating-sleeve upon said shaft, a ribbed cylinder, and ribbed hub spaced apart upon the insulating-sleeve of said shaft and coming beneath the free ends of the said groups of circuit-selectors, a bell-crank lever and other devices operated by foot-power, a jaw at one end of said bell-cranklever and a spring forming part of said jaw, said jaw engaging one end of said cam positively on'one side and by said spring in part on the opposite side and a spring-stop for momentarily holding said cam in its return movement so as to effect the sudden and complete break of the electric circuit.

9. In a device for actuating and controlling electric motors, the combination with a frame of cast metal adapted to be secured to a bench or table and having horizontal and vertical parts, of a slab of insulating material in the horizontal part, a series of pins carried thereby, series of helices stretched between said pins and forming resistances in the electric circuit, a slab of insulating material arranged in the forward part of said frame, a series of metal plates secured to said slab, a series of circuit-selectors secured -to said plate and slab, line-wires connected to the first and last of said circuit-selectors and circuit-wires extending from the intermediate circuit-selectors to the said resistances arranged in groups and to the motor, substantially as and for the purposes set forth.

' 10. In a device for actuating and controlling electric motors, the combination with a frame of cast metal adapted to'be secured-to a bench or table and having horizontal and vertical parts, of a slab of insulating material in the horizontal part, a series of pins carried thereby, series of helices stretched between said pins and forming resistances in the electric circuit, a slab of insulating material arranged in the forward part of said frame, a series of metal plates secured to said slab, a series of circuit-selectors secured to said plate and slab,

line-wires connected to the first and last of said circuit-selectors and circuit-wires extending from the intermediate circuit-selectors to the said resistances arranged in groups and to the motor, and a revoluble device, to which forward and backward movements may be imparted, located adjacent to the free ends said circuit-Selectors, substantia'lly as set forth.

11. In adevice for actuating and controlling electric motors, the combination with a frame of cast metal adapted to be secured to a bench or table and having horizontal and vertical parts, ofa slab of insulating material in the horizontal part, a series of pins carried thereby, series of helices stretched between said pins and forming resistances in the electric circuit, sheets of insulating material between and over the said series 'of helices, a slab of insulating material arranged in the forward part of saidframe, a series of metal plates secured to said slab, a series of circuit-selectors secured to said plate and slab, line-wires connected to the first and last of said circuit-selectors and circuit-wires extending from the intermediate circuit-selectors to the said resistances arranged in groups and to the motor, substantially as and for the purposes set forth.

Signed by me this 12th day of November, 1902.

orro 0. Hanson. Witnesses:

GEO. T. PINoKNEY, S. T. HAVILAND., 

